Folds in the all alpha-helix
class
III. Large Assemblies
Farnesyl pyrophosphate synthase. The active
enzyme is a homodimer; each subunit is an assembly of 14 helices.
Farnesyl pyrophosphate is an intermediate in the biosynthesis of cholesterol.
The mechanism of the synthase-catalyzed reaction is particularly interesting
since it is one of the very few known enzyme-catalyzed reactions that proceed
via a carbocation intermediate.